The subject invention relates to a gauge and method for indicating one or more properties of a loose-fill insulation in an open-front building cavity and, in particular, to a portable gauge that provides an easy to use, reliable and accurate device and method for quickly indicating the as installed density and/or the as installed thermal, acoustical, and/or other density related property or properties of a loose-fill insulation in open-front wall, ceiling, roof, and floor cavities and/or other similar open-front building cavities.
An increasingly preferred method of installing insulation in open-front wall, ceiling, roof, and floor cavities and other similar open-front building cavities is to insulate such cavities with a loose-fill insulation such as a fiberglass based, cellulose fiber based, rock wool based, or other insulation based loose-fill insulation. Such loose-fill insulations are typically introduced into these open-front building cavities by blowing or spraying these loose-fill insulations into the cavities in the form of small discrete portions of a fibrous or other insulation material or in the form of an admixture of small discrete portions of a fibrous or other insulation material and an adhesive. To be assured that these loose-fill insulations are properly installed and meeting the specifications and performance criteria set for such applications without having to utilize excessive amounts of the loose-fill insulation to assure that such performance criteria are met, it is important to be able to determine the as installed properties of the loose-fill insulation such as but not limited to the as installed thermal rating (R-value), acoustical rating (STC), combustion rating, and/or other as installed density related property of the loose-fill insulation. Since the installer of such loose-fill insulations is typically an insulation contractor, the installer should be provided with an easy to use, reliable, and accurate device and method for quickly indicating the as installed density and/or the as installed thermal, acoustical, and/or other density related property or properties of a loose-fill insulation in an open-front building cavity.
Several types of instruments and test procedures have been developed over the years to aid installers with loose-fill insulation density measurements from which the thermal, acoustical, and other density related properties of a loose-fill insulation are determined. One existing instrument measures the pressure drop across a thickness dimension of the installed loose-fill insulation material when a controlled amount of air is allowed to flow through the insulation. The pressure drop reading is then correlated with the installed density of the insulation, which in turn is correlated to the thermal or acoustical performance of the insulation. Since three-dimensional airflow characteristics exist in this type of measurement, correlation between the pressure drop reading and the insulation density is prone to considerable error and usually requires a large amount of correlation data for various types of loose-fill insulation and proposed installed loose-fill insulation densities before the instrument can be used as a tool for verifying installed properties of a loose-fill insulation. U.S. Pat. No. 6,330,779, named inventor Keven W. Kinzler, and UK Patent Application GB 2 103 695 A, named inventor David W. Anderson et al, disclose methods of blowing loose-fill insulation into a building cavity wherein the pressure at which the insulation is delivered and a sensed back pressure, respectively, are utilized to control the amount of loose-fill insulation introduced into the building cavity.
Another method for making loose-fill insulation density measurements from which the thermal, acoustical, and other density related properties of a loose-fill insulation are determined is to physically cut out or core a measured portion of loose-fill insulation from a cavity and then, weigh the removed loose-fill insulation core sample. By knowing the sample weight and volume, the as installed density of the material can be calculated. The calculated density can then be used to determine the density related insulation properties of the installed insulation. Although this can be an accurate method of density measurement, this method requires the use of a fairly accurate electronic measurement scale (e.g. depending on the sample size, this method may require an electronic scale that measures in 0.1 to 0.001 pound increments) and is usually not accurate for spray-on loose-fill insulations with high moisture contents. In addition, since most electronic scales are relatively fragile, it is not practical to provide insulation installers with these scales for day-to-day use at job sites. U.S. Pat. No. 6,047,518, named inventor Clifton E. Lytle, discloses a method for determining the density of an installed loose-fill insulation that includes the steps of locating a container of known volume and weight in a cavity, filling the container with loose-fill insulation, and weighing the filled container.
U.S. Pat. Nos. 4,712,347 and 5,287,674, named inventor Henry V. Sperber, disclose a method for determining an appropriate amount of loose-fill insulation in a building cavity wherein a netting material overlies and encloses the front of the building cavity. With this method, when the netting bulges slightly an appropriate amount of insulation is deemed to have been received and positioned within the enclosed cavity.
Another apparatus and method for determining the density of a loose-fill insulation in an enclosed cavity is disclosed in Patent Application Publication US 2005/0081604, named inventors Robert J. O'Leary et al. This patent application publication discloses a density determining apparatus for use in determining the density of loose-fill insulation within a cavity of known depth having an inner or front side covered with a sheet or netting to contain the insulation within the cavity. The apparatus comprises a sensor that senses force or a change in force exerted on the sensor by the insulation within a cavity. When measuring the density of insulation within a cavity, the sensor is held in a substantially fixed position relative to the insulation within the cavity so that the force exerted on the sensor by the insulation filling the cavity can be measured by the sensor to determine the density of the insulation within the cavity. The apparatus must be able to repeatedly hold the sensor in the same or substantially the same fixed relative position to the insulation within each cavity tested so that when the testing procedure is repeated for a series of these cavities, the density determined by the apparatus will be reliable. To sense the force of the insulation, the sensor may be supported in a substantially fixed position within the cavity by being attached to the netting or the sheathing (FIGS. 3A and 3B) or the sensor may be supported in a substantially fixed position against (FIGS. 5, 6, 7, and 9) or relative to (FIG. 8) the netting and insulation while being located outside of the cavity.